Parametric study of maximal potassium conductance on action potentials
Session Number
IND STUDY 03
Advisor(s)
Dr. Ashwin Mohan, Illinois Mathematics and Science Academy
Discipline
Independent Study
Start Date
17-4-2025 2:15 PM
End Date
17-4-2025 2:30 PM
Abstract
This study, conducted by Andrew Bae and under the guidance of Dr. Ashwin Mohan, investigated how changes in maximal potassium conductance and leak channels influence action potentials. In the first experiment, a parametric study on the maximal conductance (ḡ) was conducted, which resulted in significant changes in the action potential’s characteristics, like the time for an action potential to finish and its amplitude. At a conductance of ḡ = 16 S/cm², neurons displayed oscillatory behavior, while higher values dampened the action potentials. Extreme values, in both directions, resulted in anomalous characteristics.
Subsequently, channel variables of action potentials, such as sodium activation and inactivation, potassium activation, and their respective time derivatives, were looked into. This revealed an inverse relationship between sodium activation and inactivation, where sharp increases in dm[Na]/dt triggered rapid depolarization, followed by a delayed potassium response that repolarized the system.
Finally, the experiment ended by examining how blocking the leak channels of action potentials would affect the membrane potential and channel variables. The leak channels should be either on or off, with no in-between. When the leak channels were turned off, there was little sodium channel activation, which resulted in no depolarization.
Parametric study of maximal potassium conductance on action potentials
This study, conducted by Andrew Bae and under the guidance of Dr. Ashwin Mohan, investigated how changes in maximal potassium conductance and leak channels influence action potentials. In the first experiment, a parametric study on the maximal conductance (ḡ) was conducted, which resulted in significant changes in the action potential’s characteristics, like the time for an action potential to finish and its amplitude. At a conductance of ḡ = 16 S/cm², neurons displayed oscillatory behavior, while higher values dampened the action potentials. Extreme values, in both directions, resulted in anomalous characteristics.
Subsequently, channel variables of action potentials, such as sodium activation and inactivation, potassium activation, and their respective time derivatives, were looked into. This revealed an inverse relationship between sodium activation and inactivation, where sharp increases in dm[Na]/dt triggered rapid depolarization, followed by a delayed potassium response that repolarized the system.
Finally, the experiment ended by examining how blocking the leak channels of action potentials would affect the membrane potential and channel variables. The leak channels should be either on or off, with no in-between. When the leak channels were turned off, there was little sodium channel activation, which resulted in no depolarization.